just analysis source code is hard, can you give me some function-call stream.

and whole blueprint.

----------------------------------------------------------------------------------------------At 2010-09-10 23:47:01，"Zdenek Kabelac" <zkabelac redhat com> wrote:
>Dne 10.9.2010 17:00, yue napsal(a):
>> VolGroup00 {
>> id = "QCNEJh-9bbG-x6AV-uZEz-Dhsi-1LL7-fYSWbL"
>> seqno = 4
>> status = ["RESIZEABLE", "READ", "WRITE"]
>...
>> }
>> }//logical_volumes
>> }
>> ------------------------------------
>> how many this kind of struct is writed on raw disk,and its value???what is different??
>> how a group is parsed?
>
>
>There is always at least one back-up copy, to be able to do commit - first
>write new metadata - and when they are fully written mark them as valid. So in
>case of any write problem there is always previous last valid version
>available - see pvcreate --metadatasize --metadatasize and some other options
>in manpage)
>
>Major part of parser is located in lib/config/config.c.
>
>As for your previous question about some detailed LVM architecture document -
>well mostly only the source code itself...
>
>It would probably be better to specify what are you trying to achieve to get
>help with that ?
>
>Zdenek